Dimensional Crossover in Heavy Fermions

TL;DR

This paper characterizes the physical behavior of heavy fermions within a specific phase diagram region using one-parameter scaling, analyzing thermodynamic and transport properties, and exploring the crossover from zero to three dimensions.

Contribution

It provides a comprehensive characterization of heavy fermion behavior using the coherence temperature and explores the dimensional crossover from zero to three dimensions.

Findings

Uniform susceptibility, resistivity, and specific heat are computed.

Wilson and Kadowaki-Woods ratios are shown to be independent of the critical point distance.

The crossover from zero to three dimensions is smooth and related to spin fluctuation lifetime stiffness.

Abstract

Recently we have shown that a one-parameter scaling, the Coherence Temperature, describes the physical behavior of several heavy fermions in a region of their phase diagram. In this paper we fully characterize this region, obtaining the uniform susceptibility, the resistivity and the specific heat. This allows for an explicit evaluation of the Wilson and the Kadowaki-Woods ratios in this regime. These quantities turn out to be independent of the distance to the critical point. The theory of the one-parameter scaling corresponds to a zero dimensional approach. Although spatial correlations are irrelevant in this case, time fluctuations are critically correlated and the quantum hyperscaling relation is satisfied for $d=0$. The crossover from $d=0$ to $d=3$ is smooth. It occurs at a lenght scale which is inversely related to the stiffness of the lifetime of the spin fluctuations.